Redonkulous, or redonk, is a term that flows around my office with disturbing regularity.  It's usually prefaced by, "Jon said _____" and ends with "That's just redonk."  Thanks to Freakonomics I now know at least a little of the etymology of redonkulous: it appeared as "redunculus" over 30 years ago in the Roald Dahl book BFG.